//public class mysql {
//}
//
//Enter password: *********
//Welcome to the MySQL monitor.  Commands end with ; or \g.
//Your MySQL connection id is 10
//Server version: 8.0.39 MySQL Community Server - GPL
//
//Copyright (c) 2000, 2024, Oracle and/or its affiliates.
//
//Oracle is a registered trademark of Oracle Corporation and/or its
//affiliates. Other names may be trademarks of their respective
//owners.
//
//        Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
//
//mysql> show databases;
//+--------------------+
//        | Database           |
//        +--------------------+
//        | bit_mall           |
//        | homework           |
//        | information_schema |
//        | java113            |
//        | mysql              |
//        | performance_schema |
//        | sys                |
//        | test               |
//        +--------------------+
//        8 rows in set (0.00 sec)
//
//mysql> create database if not exists test2 (
//    -> ^C
//mysql> create database if not exists test2 character set utf8mb4 collate utf8mb4_0900_ai_ci;
//Query OK, 1 row affected (0.01 sec)
//
//mysql> use test2;
//Database changed
//mysql> show tables;
//Empty set (0.00 sec)
//
//mysql> create table if not exists student (
//    -> id primary key auto_increment,
//    -> ^C
//mysql> create table if not exists student (
//    -> id primary key auto_increment comment '学号',
//        -> name ^C
//mysql> create table if not exists student (
//    -> id int(10) primary key auto_increment comment '学号',
//        -> name varchar(20) not null comment '姓名',
//        -> sex varchar(4) comment '性别',
//        -> birth year comment '出生年份',
//        -> department varchar(20) not null comment '院系',
//        -> address varchar(50) comment '家庭住址'
//        -> );
//Query OK, 0 rows affected, 1 warning (0.02 sec)
//
//mysql> create table if not exists score (
//    -> id int(10) primary key auto_increment,
//    -> stu_id int(10) not null,
//        -> c_name varchar(20),
//    -> grade int(10),
//    -> ^C
//mysql> grade int(10)
//    -> );
//ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'grade int(10)
//        )' at line 1
//mysql> create table if not exists score (
//    -> id int(10) primary key auto_increment,
//    -> stu_id int(10) not null,
//        -> c_name varchar(20),
//    -> grade int(10)
//    -> );
//Query OK, 0 rows affected, 3 warnings (0.02 sec)
//
//mysql> show student;
//ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'student' at line 1
//mysql> desc student
//    -> ;
//            +------------+-------------+------+-----+---------+----------------+
//            | Field      | Type        | Null | Key | Default | Extra          |
//        +------------+-------------+------+-----+---------+----------------+
//        | id         | int         | NO   | PRI | NULL    | auto_increment |
//        | name       | varchar(20) | NO   |     | NULL    |                |
//        | sex        | varchar(4)  | YES  |     | NULL    |                |
//        | birth      | year        | YES  |     | NULL    |                |
//        | department | varchar(20) | NO   |     | NULL    |                |
//        | address    | varchar(50) | YES  |     | NULL    |                |
//        +------------+-------------+------+-----+---------+----------------+
//        6 rows in set (0.00 sec)
//
//mysql> show score;
//ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'score' at line 1
//mysql> desc score;
//+--------+-------------+------+-----+---------+----------------+
//        | Field  | Type        | Null | Key | Default | Extra          |
//        +--------+-------------+------+-----+---------+----------------+
//        | id     | int         | NO   | PRI | NULL    | auto_increment |
//        | stu_id | int         | NO   |     | NULL    |                |
//        | c_name | varchar(20) | YES  |     | NULL    |                |
//        | grade  | int         | YES  |     | NULL    |                |
//        +--------+-------------+------+-----+---------+----------------+
//        4 rows in set (0.00 sec)
//
//mysql>